Aggregation of multiplexed optical transceivers in server chassis to establish fabric topology

Patent metadata

Field	Value
Publication number	US-12483813-B2
Application number	US-202318098616-A
Country	US
Kind code	B2
Filing date	Jan 18, 2023
Priority date	May 4, 2022
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

This disclosure describes multiplexed optical transceivers, such as DWDM multiplexer/demultiplexers, which are aggregated in a server chassis to establish a fabric topology interconnecting blade servers to a dedicated switch module. Blade servers installed in the server chassis can utilize not just Ethernet interfaces to connect to network segments, but also PCIe interfaces as well as a combination of Ethernet and PCIe interfaces. The aggregated optical transceivers multiplex and demultiplex wavelength-specific optical signals using a laser source, reducing power consumption over switched fabric ASICs. Servicing of the multiplexed optical transceivers is facilitated by installation and replacement of a laser source. Scaling and redundancy of fabric topology interconnects can be facilitated by selection of laser sources generating expanded ranges of discrete wavelengths. Furthermore, chassis management can be facilitated by configuring network controllers of blade servers to transport chassis management instructions over the fabric topology in-band over a network interface, rather than by an out-of-band pathway.

First claim

What is claimed is:

1 . A server chassis, comprising a plurality complementary set of dense wavelength division multiplexing (“DWDM”) multiplexer/demultiplexers, a plurality of blade servers, and a laser source configured to generate a laser beam comprising a plurality of discrete wavelengths;
wherein the complementary set of DWDM multiplexer/demultiplexers each comprises a plurality of channels, a respective transponder for each channel, and a respective optical modulator for each channel, each transponder of a DWDM multiplexer/demultiplexer being configured to receive optical signals from a plurality of network ports of blade servers, and each optical modulator of a DWDM multiplexer/demultiplexer being configured to modulate a received optical signal with the laser beam to yield a wavelength-specific optical signal over respectively mutually exclusive subsets of discrete wavelengths;
wherein each blade server of the plurality of the blade servers is connected by one or more network ports to each DWDM multiplexer/demultiplexer of the complementary set of DWDM multiplexer/demultiplexers, the one or more network ports comprising an Ethernet interface and a PCIe interface;
wherein the plurality of discrete wavelengths comprises at least as many wavelengths as the plurality of channels; and
wherein the plurality of discrete wavelengths comprise at least as many discrete wavelengths as channels of a DWDM multiplexer/demultiplexer.

2 . The server chassis of claim 1 , further comprising:
a transmitting optical fiber connected to at least one of the complementary set of DWDM multiplexer/demultiplexers; a receiving optical fiber connected to at least one of the complementary set of DWDM multiplexer/demultiplexers; and an optical port; wherein the transmitting optical fiber and the receiving optical fiber are each connected to the optical port.

3 . A plurality of dense wavelength division multiplexing (“DWDM”) multiplexer/demultiplexers;
wherein the plurality of DWDM multiplexer/demultiplexers is installed in a server chassis;
wherein the plurality of DWDM multiplexer/demultiplexers each comprises a plurality of channels, a respective transponder for each channel, and a respective optical modulator for each channel, each transponder of a DWDM multiplexer/demultiplexer being configured to receive optical signals from a plurality of network ports of blade servers, and each optical modulator of a DWDM multiplexer/demultiplexer being configured to modulate a received optical signal with the laser beam to yield a wavelength-specific optical signal over respectively mutually exclusive subsets of discrete wavelengths;
wherein the laser beam comprises a plurality of discrete wavelengths comprising at least as many discrete wavelengths as channels of a DWDM multiplexer/demultiplexer; and
wherein each DWDM multiplexer/demultiplexer of the plurality of DWDM multiplexer/demultiplexers is configured to receive one or more network connections from an Ethernet interface and one or more network connections from a PCIe interface.

4 . The plurality of DWDM multiplexer/demultiplexers of claim 3 , wherein each DWDM multiplexer/demultiplexer is connected to a transmitting optical fiber and to a receiving optical fiber; and
the transmitting optical fiber and the receiving optical fiber are each respectively connected to an optical port of a server chassis.

5 . The plurality of DWDM multiplexer/demultiplexers of claim 3 , wherein a plurality of blade servers is installed in the server chassis; and
wherein each DWDM multiplexer/demultiplexer of the plurality of DWDM multiplexer/demultiplexers is configured to be connected to one or more network ports of each blade server of the plurality of the blade servers.

6 . The plurality of DWDM multiplexer/demultiplexers of claim 5 , wherein the one or more network ports comprise an Ethernet interface and a PCIe interface.

Assignees

• Cisco Tech Inc

Inventors

• Balachandran Jayaprakash
• Thakar Anant
• Sen Bidyut

Classifications

• H04J14/0307 Primary

  Multiplexers; Demultiplexers · CPC title

• H04J14/02

  Wavelength-division multiplex systems · CPC title

• H04Q2011/0073

  Provisions for forwarding or routing, e.g. lookup tables · CPC title

• H04Q2011/0052

  Interconnection of switches · CPC title

• H04Q2011/0016

  using wavelength multiplexing or demultiplexing · CPC title